Pinot Grigio from the Natural Process Alliance is served from stainless steel "Kleen Kanteen" containers at Nopa restaurant in San Francisco, Calif., on Tuesday, Mar. 24, 2009. NPA wine is made without sulfur or preservatives.

In conceiving the Natural Process Alliance, Kevin Kelley wanted to strip away all the excess of winemaking, from glass bottles to added yeast. He wanted simplicity so badly that he proposed this simple wording for the label of his new project: "Ingredients: Grapes."

Regulators scoffed. Kelley sent cellar records showing he hadn't used a single additive. He got two choices: ditch the language, or get his label rejected.

"The federal government does not believe that wine can be made just with grapes," Kelley says, "which shows you where our industry is."

The National Process Alliance wines have quickly become one of California wine's most compelling developments since they began appearing in restaurants a few weeks ago. The bottles give it away: stainless-steel water canisters from Chico-based Klean Kanteen. Kelley delivers them filled and retrieves them empty, a modern-day dairyman of sorts.

It's a novel response to the sustainability question, but it barely hints at Kelley's full plan. Already a talented winemaker for projects like Lioco and his own Salinia label, he has devised a nearly self-contained system for this wine, with a 100-mile locavore sphere drawn around his Santa Rosa winery.

Grapes are all Sonoma County. The wines are sold directly to local restaurants like San Francisco's Nopa to pour by the glass (see "From the Notebook," this page). Containers are refilled and redelivered.

That's only half the tale. Kelley's two inaugural wines, a 2008 Pinot Gris from Chalk Hill and a 2008 skin-fermented Chardonnay from a plot near Occidental, captivate by themselves. They're not so much the usual etched portrait of vintage and vineyard as the equivalent of an iPhone snap. With only about 170 cases made, this year's efforts will likely be consumed by summer.

Both are made entirely without the use of sulfur dioxide, the ubiquitous winemaking preservative. That's not unheard of; true organic wines have done it for decades, with a hardy - some argue foolhardy - handful of modern vintners following suit.

Life without sulfur raises hackles among the wine science crowd, perhaps because results are often more interesting than good. But Kelley avoided one major hurdle by devising natural wines meant for the moment.

"Especially where we live, everything is farm direct," he explains. "But wine went all the way through the production process, start to finish. This is trying to get a wine that's as fresh as possible."

If the message seems a bit woo-woo, the quiet-spoken Kelley is a good messenger. Trained at UC Davis, with an acute interest in microbiology, he's hardly radical. But in making his other wines, he found he'd already stripped off many layers of winemaking artifice - and was using native yeasts and minimal sulfur.

Still, the process needed further retooling. Grapes had to be as clean as possible. Inert argon gas is used to keep the Pinot Gris stable. The Chardonnay, since it is fermented on its skins, gets extra attention on the sorting table to pull blemished clusters. Early picking retains grapes' natural acidity, which helps as a preservative.

The winemaking is astoundingly minimal. Pinot Gris is pressed and put into a tank to ferment - on its own, no yeast added - protected by the argon, plus natural carbon dioxide released from the fermentation process. Once done, it rests until an order comes in and containers are filled from the tap. Kelley's explanation: "Mother Nature does things better than we could ever do them."

The Chardonnay is more complicated, but also the more interesting wine. After fermenting on its skins for three weeks, it ages in neutral barrels to build texture, protected by a combination of a partial vacuum created by evaporation and, again, carbon dioxide. In mid-March, it was still completing its malolactic fermentation, making the wine a bit sharp and elusive, shifting in my glass even in just a few minutes. Indeed, both wines are constantly evolving. Kelley expects each batch to be a bit different, allowing imbibers to follow the evolution.

Chris Deegan, Nopa's wine director, found that to be part of the charm. "My fear was, the wine would be terrible. But I tasted it, and I thought it was really cool," he says. "You really do get the sense that you're working with a live product."

The various pieces of Kelley's plan - reusable containers, sulfur-free living - may not be entirely new. Put them together, though, and you get a radical restructuring of the winemaking model. Something similar happened when Friuli's Josko Gravner broke out his amphorae, or when Hanzell put California wine in small French barrels.

So don't be surprised if earnest copycats appear. Kelley's delivering a quiet challenge to make wine more sustainable, canister by canister.

From the notebook

The Pinot Gris is available in a handful of Northern California restaurants, including Nopa in San Francisco, Rosso in Santa Rosa, Healdsburg Bar & Grill and Bardessono in Yountville. Prices range from about $8-10/glass and $32-40/bottle. The Chardonnay is at Terroir in San Francisco for $12/glass. More information at naturalprocessalliance.us.

2008 Natural Process Alliance Chalk Hill Pinot Gris

Edgy, sharp and fresh, with distinct mineral and shaved apple notes, and the full weight that comes with ripe Pinot Gris, but a softer ending reminiscent of Pinot Blanc. Non-fruit aromatics are at work, including a mineral twinge I associate with the carbonic maceration used in Beaujolais, perhaps due to the CO{-2} used in winemaking. At 12.4 percent alcohol, it's the lightest Pinot Gris I recall from Chalk Hill in a while.

2008 Natural Process Alliance Sonoma Coast Chardonnay

Skin-fermented. Compelling, but difficult to pin down as it's constantly changing. On first sniff, the nose offered butterscotch, scorched soil and mineral-tinged orange. Then ripe apricot showed up. There's a weighty, complex palate (perhaps from the skins; alcohol is only 13.2 percent) that still revealed sharp, tart notes. Richly textured and yet very twangy, an intriguing sum of its components. Of the two, it's the empty-glass wine; put them side by side and this one gets revisited again and again.